310 DESCRIPTION OF [Polygastrica. 



some the cells have a violet hue. These animalcules, fed 

 with colour, may be dried upon glass or mica, and thus 

 rendered permanent. The rays of the star-like vesicle 

 Ehrenberg considers as a ductus spermatici, which is long, 

 and enters the ovarium at many points. The expulsion of 

 ova has frequently been observed. The colour of these 

 animalcules, when bearing ova, is white by reflected light, 

 and yellow by transmitted, hence the names ce gold and 

 silver little fishes," so often applied to them by Joblot and 

 others ; those devoid of ova are colourless. The cilii are 

 best seen w T hen the water is coloured ; there are from 

 twenty-six to fifty-two longitudinal rows along each side 

 of the body ; in some rows Ehrenberg counted from sixty 

 to seventy cilii, which gives 3640 organs of locomotion ; 

 each cilium is placed upon a sort of little knot. Fig. 329 

 represents an animalcule dried from clear water ; Jig. 330 

 is a view of a creature feeding upon indigo, which latter 

 indicates the currents produced by its cilia ; Jig. 332 is an 

 ideal view, to shew the structure of the nutritive organs, as 

 stated by Ehrenberg ; fig. 331 is a young specimen of the 

 normal shape, hence not produced by self-division. This 

 species is abundant in vegetable infusions, and increases 

 so rapidly in stagnant waters, both by ova and self-division, 

 that some persons have thought they were produced spon- 

 taneously from elementary primal matter. Size 1-1 20th 

 to l-96th. 



511. PARAMECIUM caudatum. The tailed Paramecium. 

 Body spindle-shaped, obtuse anteriorly, but attenuated 

 posteriorly. Not found in infusions, but in ponds amongst 

 decayed sedge leaves and conferva. Size 1-1 20th. 



512. PARAMECIUM chrysalis (M.) The chrysalis Pa- 



